The present invention is generally directed to a new and improved two-way pressure relief valve and more particularly to such a valve having a single valve seat for controlling fluid flow in opposed directions through the valve.
There are many environments wherein pressure relief valves are required for substantially equalizing the pressure between an enclosed chamber relative to ambient atmospheric pressure. One such environment is in the fuel tank of an automobile or the like. In this application it is necessary to avoid the formation of a vacuum or pressure buildup in the fuel tank with respect to ambient pressure to preclude deformation of the tank. Any such deformation of a fuel tank is of course undesirable because it promotes the creation of faults in the tank which can lead to fuel leakage and the resulting danger of fire. In some cases, fuel tanks have been known to implode or explode due to the extreme pressure differentials between the inside of the tank and the outside ambient pressure.
Two-way pressure relief valves provide one solution to the foregoing problems. When the pressure within the tank decreases to the point of forming a partial vacuum, external air may be admitted to the tank to equalize the pressure. In the event of pressure buildup within the tank, air within the tank may be exhausted to the outside atmosphere to once again equalize the pressure.
Pressure relief valves for such an application must, of course, be reliable in view of the severe consequences which may result due to valve failure. Hence, such valves must be able to function properly over wide temperature extremes and for an indefinite period of time. While prior art valves have generally provided satisfactory results, there remains substantial room for improvement.
Prior valves have been relatively complex, requiring tight dimensional tolerances, and incorporating many individual component parts. This not only renders the valves expensive and difficult to manufacture, but additionally increases the possibility of component failure. Furthermore, such prior valves have been rather difficult to adjust, have included a plurality of valve seats, and have been subject to wear.
It is, therefore, an object of the present invention to provide a new and improved two-way pressure relief valve.
It is a further object to provide such a two-way pressure relief valve which includes very few component parts.
It is a further object of the present invention to provide such a valve which is simple to adjust and which includes a single valve seat.